Uncooled IR camera reveals mysteries of space

Caren B. Les, caren.les@photonics.com

Even three years after its liquid helium cooling supply was exhausted, the maverick Infrared Array Camera (IRAC) on NASA’s Spitzer Space Telescope continues to capture new and wondrous views of the universe.

Launched in 2003, the Spitzer was designed to study objects within our solar system and beyond, to the most distant parts of the universe. Most of the telescope’s other instruments lost function in spring 2009, when the “cold mission” ended.

This “tornado” nebula is one of the mysterious objects discovered through the lens of the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. The camera is sensitive to light emitted from shocked molecular hydrogen (seen in green). Scientists think the formation arises from an outflowing jet of material from a young star that has created shock waves in surrounding gas and dust. Courtesy of NASA, JPL-Caltech and J. Bally (University of Colorado).

Now in the “warm mission,” IRAC is using its two shortest-wavelength infrared sensors to image cosmic regions not visible through optical telescopes, allowing scientists to see cooler objects in space, such as failed stars, exoplanets, giant molecular clouds and organic molecules that could hold the secret to life on other planets, according to the mission overview.

IRAC captured two galaxies – the Whirlpool and its companion – in collision 23 million light-years from Earth. The camera sees the main galaxy as red due to warm dust – a sign of active star formation, probably brought about by the collision. Courtesy of NASA, JPL-Caltech and R. Kennicutt (University of Arizona).

To celebrate the warm mission’s “1000 days of infrared wonders,” NASA has released the 10 best IRAC images (some of which include data collected during the cold mission, when all four of the camera’s infrared sensors were functioning).

The full Spitzer system consists of the cryogenic telescope assembly, including an 85-cm telescope and three scientific instruments, as well as the spacecraft, which controls the telescope, provides power, handles data and communicates with Earth. The mission is managed by the Jet Propulsion Laboratory at California Institute of Technology in Pasadena.

Thanks to the quality of the images IRAC has produced, NASA’s Senior Review Panel has recommended extending the Spitzer warm mission through 2015.

Several stellar nurseries can be seen in this giant cloud. IRAC can measure the warm dust and peer into it to study the processes of new star formation. The image shows the edge of a region near the Perseus constellation. Courtesy of NASA, JPL-Caltech and Harvard-Smithsonian Center for Astrophysics.

“IRAC continues to be an amazing camera, still producing important discoveries and spectacular new images of the infrared universe,” said principal investigator Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

For more images from NASA’s Spitzer Space Telescope, visit www.spitzer.caltech.edu.